FIG. 1 is a schematic diagram of a conventional isolation circuit 150. The isolation circuit 150 is coupled between a first circuit 110 and a second circuit 190. The isolation circuit 150 includes a P-type transistor 152 and an N-type transistor 154. The isolation circuit 150 can selectively couple or isolate the first circuit 110 and the second circuit 190 according to a signal S1 and a signal S2.
However, the conventional isolation circuit 150 probably cannot assuredly couple (or assuredly isolate) the first circuit 110 and the second circuit 190 due to characteristics of the P-type transistor 152 and the N-type transistor 154. For example, when the first circuit 110 and the second circuit 190 are required to be coupled, a signal transmitted between the first circuit 110 and the second circuit 190 can be probably truncated due to a body effect of the P-type transistor 152 and/or the N-type transistor 154.
When the first circuit 110 and the second circuit 190 are required to be isolated, the P-type transistor 152 and/or the N-type transistor 154 probably form a leakage path for leaking the signal from the first circuit 110 to the second circuit 190 or from the second circuit 190 to the first circuit 110.